The present invention relates to a lancet device for puncturing the skin of mammals, especially of humans, and comprises an insert with a grip element as well as a bushing with a grip portion, the bushing receiving the insert in an axially slidable manner, whereby the insert at its free end remote from the grip element is provided with a lancet having a tip for puncturing the skin.
Lancet devices for puncturing the skin, especially of humans, are known and are successfully being used in various embodiments in ambulatory facilities, in hospitals, in physicians practices, in red cross facilities as well as in emergency facilities, etc. in order to draw small amounts of blood for blood testing. An essential requirement for such lancet devices is that they must be producible at extremely low cost because they are used in great numbers in the aforementioned institutions and must be provided in great numbers at these facilities. A further essential requirement for these lancet devices that at least the portion of the lancet device that directly penetrates the skin of a human, i.e., that is directly in contact with the tissue beneath the skin and the blood stream of the human, must be maintained in sterile conditions until they are being used. In general, the portions of the lancet device which penetrate the tissue to a predetermined depth in order to connect with blood vessels for collecting the blood emerging from the penetration opening, are so-called lancets which have a substantially circular cross-section and are comprised of a steel body having a pointed end for puncturing the skin.
In general, such lancet device, after being used once for the designated puncturing function are not being reused because a subsequent sterilization of the lancet device is much more expensive than the manufacture of such a lancet device. Thus, the aforementioned lancet devices are usually single use devices.
From German Patent 31 11 737 a lancet device of the aforementioned kind is known. This lancet device is comprised of a bushing and an insert whereby the insert is provided with a lancet having a pointed end for the puncturing the skin at a free end of the insert remote from a corresponding grip element. The insert is provided with a radially extending peripheral bead portion which is arranged at the shaft-like insert at a predetermined distance to a pressure plate. The end of the insert remote from the peripheral bead portion which is also embodied as a shaft is arranged in the bushing which has an interior corresponding to the shaft cross-section of the insert. From the free end of the shaft of the insert the pointed end of the lancet projects. For performing the designated puncturing function with the known lancet device, the insert is in general axially displaced by the thumb of the operator via the grip element whereby the peripheral bead portion is pressed over corresponding radially inwardly extending bead provided at the interior of the bushing and projecting into the travel path of the insert; whereby the two beads are elastically deformed for overcoming their resistance relative to one another. After the resistance has been overcome the bead portion of the insert glides over the bead portion of the bushing and the lancet tip can puncture in the predetermined manner the skin, respectively, the tissue of the human, to a predetermined depth.
The known lancet device has substantial disadvantages. On the one hand, already during insertion of the insert element into the bushing the lancet tip can lose its sterility when, for example, the operator inserting the insert into bushing touches with the lancet tip the grip element at the inlet opening of the bushing element or touches his own skin. In summarizing the above, it can be said that during the introduction of the insert into the bushing a plurality of possibilities for desterilizing the lancet are present which is of special concern with respect to the treatment of HIV patients.
Even though in the known device the lancet tip is embedded within the material of the bushing, i.e., the insert and the bushing are manufactured in one step in the form of a single part by injection molding so that the sterility of the lancet tip in so far is completely guaranteed, in any case must the insert be removed from the bushing for the use of the lancet tip in order to be inserted into the bushing in the aforedescribed manner, whereby due to the required separation the lancet tip is freed and thus exposed to microbiological bacteria and viruses and other contaminants.
A further important disadvantage of the lancet device is that the release mechanism, depending on the manufacture and sensitivity of the operator using the lancet device is released with different velocities and thus applied with varying success so that the puncturing is not carried out in the required manner at all times, i.e., resulting in the required blood flow from the opening that has been made in the skin of the human.
It is furthermore disadvantageous that this known lancet device can only be manufactured in a very complicated and thus very costly process due to the absolute sterility requirements for at least the lancet tip.
It is therefore an object of the present invention to provide a lancet device of the aforementioned kind which is simple in its construction and thus less expensive to manufacture than the known lancet devices, which furthermore remains absolutely sterile until immediately before its use for puncturing the skin of a human, which consistently provides for a uniform puncturing function of the lancet tip for penetrating the skin of a human independent of the individual characteristics of the operator, and which furthermore after its use ensures that the lancet tip is protected so that no accidental injuries and resulting infections by the blood sticking to the lancet tip can occur.